Prevalence of Oral Candida Infections in Diabetic Patients

Objective: The purpose of this study was to determine the prevalence, species distribution and antifungal susceptibility profile among oral cavity isolates of Candida species from diabetic and non-diabetic subjects. The contribution of smoking and dental status to the prevalence and distribution of Candida species was also evaluated. Design: Retrospective study of oral cadidiasis in diabetic patients between January and October 2003 was undertaken. Setting: Three private clinics in Amman, Jordan and Department of Biological Sciences at Hashemite University. Method: A total of 262 individuals were enrolled in the study, 132 were diabetics and 130 healthy controls. None of the non-diabetic controls had any clinical evidence of oral candidiasis, 8.3% of diabetics had clinical evidence of oral candidiasis, of which, 36% were overnight denture wearers and tobacco smokers. An imprint culture method was used to determine the frequency of isolation and density of Candida species at up to nine intra-oral sites. Yeast-like colonies were identified by classical methods and CHROMagar Candida medium. Broth macrodilution technique was used to determine the antifungal susceptibility pattern of Candida isolates. Results: Positive yeast was detected in 58.3% of diabetics compared with 30% in healthy controls (P<0.001). C. albicans was the most prevalent species in both diabetics (81.8%) and controls (76.9%) followed by C. tropicalis, C. parapsilosis and C. glabrata. C. kefyr and C. krusei were isolated only from diabetics at a combined rate of 1.3%. Candida was detected more frequently in diabetic denture wearers than in control counterparts in all anatomic sampled sites (P<0.05). The frequency of Candida isolation was significantly higher in smokers than in the non-smokers in both diabetics and controls (P<0.001). All C. albicans recovered from diabetics and controls were susceptible to amphotericin B, ketoconazole, itraconazole and fluconazole. Non-albicans Candida isolates were shown to have higher azole MIC values than C. albicans isolates. Conclusions: Our findings show that smoking and continuously worn dentures, promote oral candidal colonization in diabetics.